The present invention relates to a new and distinct cultivar of Rhododendron, also commonly known as evergreen azalea, which is grown as an ornamental shrub for use in planted containers and in the garden and landscape. The new cultivar is known botanically as Rhododendron kaempferi hybrid, and will be referred to hereinafter by the cultivar name ‘WALPINRUF’.
‘WALPINRUF’ arose and was selected from a long term breeding program commenced in 1993 or 1994. The aim of the breeding program was to develop one or more matched series of novel cultivars of hardy evergreen azaleas with showy flowers. Breeding commenced with Azalea ‘Elsie Lee’ as one of the initial parents. Azalea ‘Elsie Lee’ is a Shammarello hybrid, raised in Ohio in the 1960s and renowned for its relative hardiness among evergreen azaleas. Although several Shammarello hybrids were patented in the 1960s and 1970s, Azalea ‘Elsie Lee’ is believed to be unpatented. ‘Elise Lee’ bears light mauve-blue semi-double flowers.
Commencing in 1993 or 1994, many generations of deliberate hybrids were raised, selecting promising parents from previous unnamed seedlings which had been raised during the breeding program. ‘WALPINRUF’ was selected in 2003 or 2004. The parents of ‘WALPINRUF’ are unknown and have not been retained: no parental comparison information is available.
Asexual propagation of ‘WALPINRUF’ was first accomplished in 2003 or 2004 using semi-ripe shoot cuttings. Since that time, under careful observation, the distinguishing characteristics of ‘WALPINRUF’ have been determined stable and uniform, and to reproduce true to type in successive generations of asexual propagation.